Analysis of arc welding process using Digital Storage Oscilloscope

During welding, random variations in current and voltage occur, which cannot be recorded with ordinary ammeter and voltmeter. Acquisition of voltage and current signals while welding is in progress at a very high speed using Digital Storage Oscilloscope (DSO) and subsequent analysis of the stored data can be very useful to understand the arc welding process. In the present study, welding data were acquired for two inverter and two generator power sources while welding with two different electrodes using a DSO at the sampling rate of 40,000 samples/s. This data was filtered using the Fast Fourier Transform (FFT) low pass filter and subjected to time domain and statistical analysis. Probability Density Distributions (PDDs) were used to evaluate performance of power sources and consumables. Results clearly differentiate between the arc characteristics for different power sources and consumables.